Insulated electrode



Oct. 6, 1959 J. M. STANLEY INSULATED ELECTRODE Filed Sept. 5. 1957 INVEJOSEPH M.

NTOR,

STA N L E Y .arromvsx' United States Paten 2,907,808 INSULATED ELECTRODEJoseph M. Stanley, Spring Lake, N.J., assignor to the United States ofAmerica as represented by the Secretary ofthe Army Application September5, 1957, Serial No. 682,264 6 Claims. (Cl. 136-4) (Granted under Title35, Code (1952), see. 266) This invention relates to a method ofproducing a quartz and used by. or forthe Government for governmentalpurposes, without the payment of any royalty thereon.

This invention relates to a method of producing a quartz crystalinsulated electrode and to the quartz crystal insulated electrodeproduced by such a method. The present invention is particularlyapplicableto the production of an insulated electrode that is suitablefor use in measuring the temperature and/or determining the conductivityconditions inside a sealed autoclave used for quartz growth though notlimited thereto.

It has been customary in theart of growing crystals by hydrothermaltechniques to make indirect temperature measurements of this type usingthermocouple wells. Usually, such measurements may not have given theactual temperature of the crystallizing solution in the autoclave due tothe mass of metal comprising the thermocouple well existing between thethermocouple and the crystalliz- Patented Oct. 6, 1959 has a naturaltendency to grow more rapidly along its X and Z axes than along its Yaxis. Satisfactory dimen--- Crystal 10 is in the form of a rectangularblock, and i the face 12 and its opposite face are slotted parallel tothe X-axis, substantially at their mid-point to provide grooves 16 and18 respectively therein. A non-corrosive conducting wire 20 such assilver, gold, platinum or any alloy of gold or platinum is looped aroundthe length of crystal 10 and is recessed in.the grooves 16 and 18 to ingsolution. In addition, previous measurements of conductivity of thecrystallizing solutions were not uniformly successful due to thedevelopment of leaks in the ceramic seal of the insulated electrode andto the occurrence of corrosion therein.

The present invention is intended and adapted to overcome thedifiiculties and disadvantages of the prior art and to provide a new andimproved method of making a more eflicient insulated electrode whichsubstantially avoids one or more of the limitations of the describedprior devices used for making conductivity and/or temperaturemeasurements of the crystallizing solution in an autoclave.

In accordance with the invention the quartz crystal insulated electrodeis formed by winding a non-corrosive Wire to be used as the electrodearound a Y-bar quartz crystal seed, and depositing synthetic quartzthereon, under conditions suitable for the growth of synthetic quartz,so as to completely 'cover the wire.

The features of the invention which are believed to be novel are setforth with particularity in the appended claims. ,The invention itself,however, both as to its organization and method of operation, togetherwith further objects and advantages thereof, may best be understood byreference to the following description taken in conjunction with thefollowing drawing, wherein:

. Fig. 1 is a isometric view of a Y-bar quartz crystal including a wireelectrode constructed in accordance with the invention; a

Fig. 2 is a cross-sectional view of an autoclave with which theelectrode of Fig. 1 may be used; and V Fig. 3 is an isometric view,partially cut away, of another embodiment of the invention showing aY-bar quartz crystal including a pair of thermocouple wire electrodes.

In Fig. 1 of the drawing, there is 'shown a water-insoluble Y-bar ofnatural or synthetic'quartz seed 10 illus-Q trating its X, Y and Z axis;Crystal 10 is suitable for depositing on its surfaces syntheticcrystalline quartz and uniformly position the wire thereon. The ends ofwire 20 extend beyond the ends of crystal 10 along the Y-axis.

to terminate on opposite ends of bar 10, as shown.

The assembly is then placed in an autoclave containing quartz growthcrystallizing solution, and using standard techniques forhydrothermalgrowth for synthetic quartz, the Y-bar seed 10 is built upto a quartz crystal. The growth is continued until a layer 14 ofsynthetic quartz completely seals and covers Y-bar seed 10 and wire 20.When this treatment is, completed, the grown quartz crystal is removedfrom the autoclave and is cut and processed to form a quartz crystal 21tapered at each end to provide a suitable air-tight seat when theinvention is used as an insulated electrode in an autoclave setup, whichwill be described hereinafter. The body of the completed quartz crystal21 may retain its square cross-sectional form as shown in. Fig. 1, or.it may be processed into a cylinder, so long as wire 20 is not ex-.posed.

v For a detailed description of the use of the invention; reference ishad to Fig. 2, wherein the device shown in I Fig. 1 is described inconnection with an autoclave used in making measurements of theconductivity of the crystallizing solution. The autoclave does notconstitute any part of the invention.

The autoclave22is a pressure vessel useful for growing synthetic quartzcrystals from'a crystallizing solution 26, which is contained in a.stainless steel tank or other suitable metal container 28 arranged to beheated electrically or by any other means and maintained at an elevatedtemperature of between 350 and 400 degrees centigrade and operating at apressure roughly between 400 and 800 atmospheres. Container 28 may beclosed at its top with a cover 30 made of stainless steel or othersuitable metal which may be held against container 28.

with a suitable clamp and makes an air-tight seal there with by means ofa soft copper gasket 32 fitted into grooves 34 and 36.

The cover 30 is bored vertically at its top to provide" the threadedrecess 38 therein. The opposite end 40 is provided with a central boreor aperture 42 which extends vertically through the cover, flaringoutwardly .at 44 and opening into the elongated channel 46. The chann'el46 in turn opens out into recess 38. Confined within the channel 46 isthe Y-bar insulated quartz electrode 48 illustrated in Fig. 1, havingboth tapered endsStl and 52 provided with wire terminals 54 and 56respectively.

Quartz insulator 48 is supported in an airtight sealed position by ametal gland nut 58, which has a hollowed-out portion 60 to receivetapered end 50 of electrode 48 when gland nut 58 is threaded into recess38. Tapered end 52 fits securely in flared out portion 44 and forms anair-tight seal therewith. I 7

When cover 30 is clamped against container 28, wire 56 is immersed intocrystallizing solution 26. The other electrode 54 is brought through areduced central opening 62 in gland nut 58 and is insulated therefrom bymeans of a ceramic tube 64 that completely surrounds electrode 54. Awire 66, connected to the outer wall of container 28'making electricalcontact therewith and wire Fig. 3 shows an embodiment of the inventionused for measuring the-temperature of a crystallizing solution atelevated temperatures and'pressures.

In, this embodiment dimensions for the rectangular block of'Y-bar seed82 of natural or synthetic quartz that is used as a nucleus to grow thecompleted quartz crystal 70 may be 1 inchin length by A inch'square incrosssection. A pair of spaced grooves 72 and'74, parallel to the X-axisare provided in face 76 of the Y-bar seed 82 and a corresponding pair ofgrooves 78 and 80 are provided in the opposite parallel face. Twonon-corrosive thermocouple wires 84 and 86, having different thermalcharacteristics such asplatinum and platinum-rhodium oithe like, arespaced from each other and separately looped around the length of Y-barseed 82 parallel with the Y-axis. Wire 84 is Wound in grooves 74 and 78,and

wire 86 is wound in grooves 72 and 80 in the face '76 and its oppositeparallel face. The lower extremities of wires 84 and 86 are fusedtogether atbead 88. The assembly is: then suspended in an autoclave andsynthetic'quartz is deposited thereon by conventional hydrothermalmethods' until the Y-bar seed 82 and the thermocouple wires 84 and 86are completely covered by synthetic quartz in ajmanner similar to thatdescribed hereinbefore for the Y -bar seed 10. When s'ufiicient quartzhasbeen grown on Y-bar seed 82 it is removed from the autoclave and theends are tapered to form the completed crystal 70 as shown. In this 'onethe body of the quartz crystal 70 is formed as a cylinder.

The completed crystal 70 may then be used in an autoclave, as describedabove in Fig. 2. However, in this embodiment the two ceramic insulatedthermocouple wires 84 and 86 are brought through the reduced centralopen ing 62 in gland nut 58. Head 88 is immersed into the crystallizingsolution sufficiently to make proper thermal contact therewith, and astandard current measuring in strurnent '(not shown) is connected toelectrode wires 84 and 86. The current produced by the thermocouple is ameasure of the temperature.

Although in the specific embodiments only quartz is shown in producingthe insulated electrode,other crystalline materials grown eitherhydrothermally or at approximate room temperatures and at atmosphericpressures may be used. However, such other crystalline materials shouldnecessarily be water insoluble and mechanically strong.

While there has been described what are at present considered to be thepreferred embodiments of the invention,

it. will be obvious to those skilled in thevart that various changes andmodifications may be made therein without departing from the invention,and it is, therefore, aimed in the appended claims to cover all suchchanges and modifications as fall within the true spirit'and scope ofthe invention.

i What is claimed is:

1. The method of producing an insulated unitary electrode comprisinglooping a continuous'non-corrosive conducting wire around asubstantially rectangular body of Y-bar seed of water insolublecrystalline quartz having opposite elongated faces parallel to itsY-axis, said looping being parallel to said Y-aXis, and growingsynthetic quartz on said seed and over said wire to form a singlecrystal.

2. The method of producing an insulated unitary electrode comprisinglooping a continuous non-corrosive conducting wire about a"substantially rectangular body of Y-bar seed of crystalline quartzhaving opposite elongated faces parallel to its Y-axis, said loopingbeing parallel tos'aid Y-axis, extending the discrete ends of said wirebeyond the boundaries of said seed to form terminals, and growingsynthetic crystalline quartz on said seed and over said Wire to form asingle crystal.

3. The method of producing an insulated unitary electrode'comprisinglooping a pair ofadjacent continuous non-corrosive conducting wireshaving different thermal characteristics on a substantially rectangularbody of Y-bar seed of crystalline quartz having opposite elongated facesparallelto its Y-axis, said looping being parallel to said Y-axis,extending to discrete ends of, said wires beyond to boundaries of saidseed to form terminals, fusing one pair of said extended adjacentwiresto form a thermocouple, and growing synthetic-crystalline quartz onsaid seed and over said wire.

4. An insulated unitary electrode comprising a substantiallyrectangular'body of Y-bar seed of crystalline quartz having oppositeelongated faces parallel to the Y-axis of said seed, a continuousnon-corrosive conducting wire on said elongated faces parallel to saidY-axis and having its ends extending beyond the boundaries of said seedto form terminals, and synthetic crystalline quartz grown on said seedand over said wire.

5. An insulated unitary electrode comprising a substantially rectangularbody of Y-bar seed of Water insolua ble'quartz having opposite elongatedfaces parallel to its Y-axis, and a non-corrosive conducting wire'imbedded therein parallel to said Y-aXis having ends extending fromReferences Cited in the file of this patent UNITED STATES PATENTS2,456,831 Kjellgren 'Dec. 21, v1948 2,546,305 Jatfe et"al.' "Mar. 27,1951 2,638,408 Friedman et al May 12, 1953 2,680,677 Broge et al. "June8, 1954 2,794,059

Smith May 28, 1957

